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A. H. POLLEN AND H. ISHERWOOD.

ELECTRIC FIRE CONTROL FOR GUNS.

APPLICATION FILED APR. 3. 1919.

1 314,208. PutentedAug. 26,1919.

3 SHEETSSHEET l- A. H. POLLEN AND H. ISHERWOOD.

ELECTRIC FIRE CONTROL FOR GUNS.

APPLICATION FILED APR. 3. 19w.

1 ,3 14,208. Patented Aug. 26, 1919.

3 SHEETSSHEET 2- A. H. POLLEN AND H. ISHERWOOD.

ELECTRIC FIRE CONTROL FOR-GUNS.

APPLICATION FILED APR. 3. 1919.

Patented Aug. 26, 1919.

3 SHEETSSHEET 3.

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WITNESS: INVENTORS A M fl olww Buckin mTED S A ES PATENT. orrron.

,Anrnun n. roman, or LONDON, AND mom) ISEER'WOOD, or YORK, ENGLAND.

' ELECTRIC FIRE CONTROL FORGUNB.

' To all whom it mag concern:

'Pomam and HAROLD srmmvoon, subjects of of Great Britain, residing atl l am street, Strand, London W. C., and Bis ophill House, York, Yorkshire, respectively, have invented certain new and usefulIm rovements in Electric Fire Controls for uns, of which the following is a specification v the King This invention consists in means for op-- crating the receiver at the gun of the type known as the follow the ointer receiver in a particular way, name y,- by settlng on the transmitter the rate of change of range Thus if it is known'that the range for example is increasing at the rate of 500 yards a minute, the rate of chan e is set dial at the transmitting en and the up on a follow the pointer receiver? will, according to this invention, be caused to change its indications at this rate.

There is no particular novelty in the general problem of setting a receiver to operate at a particular rate of change of ran e, and

. several mechanisms have beendescri ed by ourselves and others operating on this principle, as far as we are aware however, the principle has not been, applied to the particular instrument known as follow the pointer receiver.

Special means are required for the aplication of the principle to this particular instrument owing to the fact that its scale of ranges may not be uniform, but may have Wider graduations at short ranges than at 'long ones, or may have wider graduations at the long ranges than at the short ranges depending upon the mechanism between the dial and the sight itself. a

In the accompanying drawings:

Figure 1 is a plan view partly in section of a mechanism embodying our invention.

Fig. 2 is a sectional elevation of a modified form of thesame.

Fig. 3 is a diagrammatic view showing the follow the pointer receiver and the connections for operating it from the transmitting station.

Referring to the drawings:

The operative parts of our novel mechanism are mounted in and sustained by a suitable frame or casing A having a to B and covered by a suitable lid or cover as shown in Fig. 2.

Referring first to'Figs. 1 and 3, 1 is an SpecificationofLetters latent.

Patented Aug. 26, 1919.

Application filed April 3, 1919. Serial in. 287,328.

insulated cylinder carrying contacts co-act- I by step, and by suitable g'earin sttzlp ,w l impart a like motion to the pointer a follow the pointer receiver as shown in Fig. 3, which pointer is adapted to be read 1n connection with graduations on a scale H similar to the scale 6 before alluded to. The cylmder 1 is mounted on a'shaft 7 journaled n bearm on the casing A which shaft 1s manual y rotated by the handle 2 at the requisite speed, which speed is determined 1n the manner hereafter described. The rotations of the shaft 7 represent range and are indicated by means of a pointer 5 travelmg over a range scale 6 sustained by the top B of the casing, the pointer being carried by a vertical shaft 9 journaled in a bearing 9 sustained by the top of the casing. The shaft has a worm wheel 9 fixed to it which meshes with a worm'9 on the shaft 7. It will be observed that the scale (which corresponds to the scale of the well known follow the pointer receiver) is far more open at short rangesthan "at long ranges. In order. that the operator may know at what rate the handle ought to be turned in order to impress on the follow the, pointer receiver the definite rate of change of range desired we provide a well known device consis'ting of a friction driven variable speed mechanism comprising the driving roller 8 splined to the shaft 7 which roller engages and frictionally drives the disk 10 wlth a variable speed ratio depending upon the distance of the roller 8 from the center of the disk 10. The disk 10 is carried by a vertical shaft 10 rotatably mounted in a bearing in the top B of the casing, which shaft carries 35- engages a pinion 36 fixed to the lower end of a stem 37 mounted in a bracket bearing 38 sustained by the casing top, a housing 37 X being fixed to the upper end of the stem a inion 34 engaging a gear wheel 35 mount e in a bearing on the casing top. The gear this motion of the second hand is reduced to zero, that is he always turns the handle at such a speed that the watch itself is rotated counter-clockwise once a minute. This is facilitated by means of a line 13 engraved on the glass which covers the hole in the 11d, the 'said line intersecting the axis of the second hand of the Watch. By these means the disk 10 is always driven at a constant speed and the shaft 7 is rotated by the-operator at the required variable speed. The positlon of the roller 8 on the disk 10 is determined by setting the pointer 15 which indicates against the rate-of-change-of-range scale 14L to a certain rate of change of range. The pointer 15 is carried by a shaft 15 mounted in a bearing on the lid C and has a plnion 16 fixed to its lower end which engages rack teeth on a slide 17 mounted to move in a guide 18 sustained by the casing top; A

' link 19, provided with two longitudinal slots 19 and 19", is pivoted at one end as at 19 to the slide 17 and is fulcrumed between itsends on a pivot stud 20 extending through the slot 19. This link is pivoted at its opposite end to a slide 9 by means of a pivot pin 9 extending through the slot 19 and carried by the slide 9. The slide 9 is provided with an arm 9 which is forked at its end and engages on opposite sides on the roller8 on the shaft 7. As a result of the construction and operation of the parts i above described, when the pointer 15 is set by means of a knurled head 40, with reference to the graduations on the scale 14, the slide 17 will be shifted, the link 19 swung about its pivot 20, and the slide 9 shifted, thereby setting the roller 8 at a given definite distance from the axis of the disk 10.

We do not claim any novelty in .the mechanism so far described, which however would only operate correctly on a receiver whose range graduations were equal at all parts of the scale.

We now proceed to describe the improvements which have been made by us for adapting the mechanism already described to operate with the unequal scale of the followthe pointer receiver shown in Fig. 3.

To this end we provide means for shifting the pivot 20 about which the link 19 rocks so as to give a faster angular speed to the receiver at short range than it has at long ones. This is .done by means of a screw cam groove 23 cut in a cam cylinder 24 which cylinder is rotatably mounted on center bearings sustained by the top B of the casing and is geared to the shaft 7 by the worm gear 24 shown in Fig. 1. The pivot stud 20 before alluded to, is carried by a slide '21 mounted to move in a guiding slot in a bar 212" sustained by the top B .of the casing, and a pin 22 depends from the end of said slide and engages with the groove 23 of the cam cylinder and shifts the pivot 20 laterally in of the mechanism being driven by an elec-' tric motor, instead of driving the shaft 7 as above described we prefer in this case ,to

drive the variable speed disk 10 from the motor M through the worm gears 30 and 31, shaft 32 and spur gears 33 and 34. The shaft 7 is then driven from the variable speed mechanism at a suitable rate by manually controlling the speed of the motor M so that the second hand of the watch is reduced to rest. This control is efiected by cutting in and out resistance on the coil 25 by means of a slide contact I shown in Fig. 2. All that is necessary with this form of the mechanism is to set up the required rate of change of range on the dial 14 by means of the knurled head 1U and to continually adjust the slide contact so as to maintain the second hand of the watch 12 in coincidence with the line 13 engraved on the glass above it.

What we claim is 1. In electrical fire control apparatus for guns of the kind in which motion is transmitted to a pointer at a receiving station by means of a rotary shaft at a certain speed determined by an indicator at the transmitting end and, in which the speed of :rotation transmitted is governed by the position of a roller in a roller-'and-disk variable speed gear the position of the roller being determ ned according to the indication of the aforesaid indicator, means for varying the speed of rotation transmitted to compensate for variations in the scale readings of a scale which does not-follow a straight line law, consisting in mechanism for transmittin motion to the roller from the indicator, 111 which mechanism the indicator rocks one end of a link about a movable pivot engaging in a slot in the link the other end of the link being connected to the roller, the position of the pivot being determined by a suitably constructed cam driven from the shaft on which the roller is mounted, so that the velocity transmitted is varied according to the position of the pivot, that is, according to the part of the scale on which the indication on the scale is being made.

. 2. In a'mechanism of the type described, the combination of a movable transmitter pointer, a rotary shaft for moving the pointer, a variable speed gear cooperatin with the shaft and including a rotary disk and a wheel movable with the shaft and in frictional engagement with the disk and movable bodily radiall of the disk, an indicator movable to in icate the rate of change of range, a member operatively connecting the indicator with the wheel and acting, when the indicator is moved, to move the wheel radially of the disk, a follow the pointer receiver comprising a movable receiver pointer and an associated scale which does not follow a straight line law, means whereby said receiver pointer is moved by the shaft, and a device operated by the shaft and controlling the radial movements of the wheel, for automatically varying the velocity transmitted by the shaft 1n order to compensate, in the movements of the re ceiver pointer, for the variations in the scale of the follow the pointer receiver.

3. In a mechanism of the type described, the combination of a movable transmitter pointer, a rotary shaft for moving the pointer, a variable speed gear cobperatin with the shaft and including a rotary dis and a-wheel splined to the shaft and in frictional engagement with the disk and movable on the shaft radially of the disk, anindicator movable to indicate the rate of change of range, a link operativel connected atone end with the indicator to he moved thereby, a movable fulcrum pin on which the link is fulcrumed between its ends, a slide connected with the opposite end of the link and engaging the wheel to move the same radially of the disk, when the link is swung on its fulcrum by the indicator, a follow the pointer receiver comprising a movable receiver pointer and an associated scale which does not follow a straight line law, means whereby said receiver pointer is moved by the shaft, a rotary device operated by the shaft, and connections between said rotary device and the fulcrum of the link to move said fulcrum relativel to the link longitudinally thereof; whereby the velocity transmitted by the shaft will be automatically varied in order to compensate in the movements of the receiver pointer for the variations in the scale of the follow the pointer receiver.

In testimon whereof we have hereunto set our hands in presence of the subscribing witnesses.

ARTHUR POLLEN. HAROLD ISHERWOOD.

Witnesses for A. H. Pollen:

NEVILLE E. BROOKES, ERNEST J. HILL.

VVitnesSes for H. Isherwood:

ARTHUR J. HALL, 

